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| n | a(n) |
|---|---|
| 1 | 1 |
| 2 | 3 |
| 3 | 14 |
| 4 | 76 |
| 5 | 488 |
| 6 | 3521 |
| 7 | 28009 |
| 8 | 241590 |
| 9 | 2223711 |
| 10 | 21519533 |
| 11 | 216099699 |
| 12 | 2228023793 |
| 13 | 23394765858 |
| 14 | 248722671553 |
| 15 | 2666496996271 |
| 16 | 28746778089814 |
| 17 | 311062415257234 |
| 18 | 3374225209472645 |
| 19 | 36661349689794535 |
| 20 | 398760168220542400 |
[1,3,14,76,488,3521,28009,241590,2223711,21519533, 216099699,2228023793,23394765858,248722671553, 2666496996271,28746778089814,311062415257234, 3374225209472645,36661349689794535, 398760168220542400] |